Nonlinear optical properties of Ag@SiO2 core-shell nanoparticles investigated by continuous wave He-Ne laser

Sakthisabarimoorthi, A.; Dhas, S. A. Martin Britto; Jose, M.

doi:10.1016/j.matchemphys.2018.03.047

Cited by 51 publications

(12 citation statements)

References 29 publications

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“…Fourier-transform infrared spectroscopy (FTIR) was performed to analyze changes in the functional groups of the samples and to verify the formation of the composite EVA-SiO 2 -Ag ( Figure 3 ). For SiO 2 -Ag, there is a broad band located near 3400 cm −1 and another located at 1627 cm −1 , both corresponding to the O–H stretching of water and the formed silanol groups (Si–OH), respectively [ 92 , 93 ]. The bands observed at 1100 and 475 cm −1 , on the other hand, are attributed to symmetrical stretching and bending of Si–O–Si bonds, respectively [ 92 , 94 , 95 ].…”

Section: Resultsmentioning

confidence: 99%

“…For SiO 2 -Ag, there is a broad band located near 3400 cm −1 and another located at 1627 cm −1 , both corresponding to the O–H stretching of water and the formed silanol groups (Si–OH), respectively [ 92 , 93 ]. The bands observed at 1100 and 475 cm −1 , on the other hand, are attributed to symmetrical stretching and bending of Si–O–Si bonds, respectively [ 92 , 94 , 95 ]. The peaks located at 950 and 845 cm −1 indicate the bending of the O–Si–O moiety [ 80 , 95 ].…”

Section: Resultsmentioning

confidence: 99%

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SiO2-Ag Composite as a Highly Virucidal Material: A Roadmap that Rapidly Eliminates SARS-CoV-2

et al. 2021

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COVID-19, as the cause of a global pandemic, has resulted in lockdowns all over the world since early 2020. Both theoretical and experimental efforts are being made to find an effective treatment to suppress the virus, constituting the forefront of current global safety concerns and a significant burden on global economies. The development of innovative materials able to prevent the transmission, spread, and entry of COVID-19 pathogens into the human body is currently in the spotlight. The synthesis of these materials is, therefore, gaining momentum, as methods providing nontoxic and environmentally friendly procedures are in high demand. Here, a highly virucidal material constructed from SiO2-Ag composite immobilized in a polymeric matrix (ethyl vinyl acetate) is presented. The experimental results indicated that the as-fabricated samples exhibited high antibacterial activity towards Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as well as towards SARS-CoV-2. Based on the present results and radical scavenger experiments, we propose a possible mechanism to explain the enhancement of the biocidal activity. In the presence of O2 and H2O, the plasmon-assisted surface mechanism is the major reaction channel generating reactive oxygen species (ROS). We believe that the present strategy based on the plasmonic effect would be a significant contribution to the design and preparation of efficient biocidal materials. This fundamental research is a precedent for the design and application of adequate technology to the next-generation of antiviral surfaces to combat SARS-CoV-2.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

SiO2-Ag Composite as a Highly Virucidal Material: A Roadmap that Rapidly Eliminates SARS-CoV-2

et al. 2021

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“…In addition to the bands associated with Si-O-Si vibrations, there are bands in the spectrum that can be assigned to the bending vibrations of OH, such as this at 1640 cm −1 which can be caused by H 2 O deformation. Moreover, there are other bands corresponding to OH stretching vibrations which are located at 3420 cm −1 , whereas the shoulder located near 3750 cm −1 can be attributed to the Si–OH group in the silica shell [ 48 , 49 ].…”

Section: Resultsmentioning

confidence: 99%

Dansyl-Labelled Ag@SiO2 Core-Shell Nanostructures—Synthesis, Characterization, and Metal-Enhanced Fluorescence

et al. 2020

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The present work describes synthesis, characterization, and use of a new dansyl-labelled Ag@SiO2 nanocomposite as an element of a new plasmonic platform to enhance the fluorescence intensity. Keeping in mind that typical surface plasmon resonance (SPR) characteristics of silver nanoparticles coincide well enough with the absorption of dansyl molecules, we used them to build the core of the nanocomposite. Moreover, we utilized 10 nm amino-functionalized silica shell as a separator between silver nanoparticles and the dansyl dye to prevent the dye-to-metal energy transfer. The dansyl group was incorporated into Ag@SiO2 core-shell nanostructures by the reaction of aminopropyltrimethoxysilane with dansyl chloride and we characterized the new dansyl-labelled Ag@SiO2 nanocomposite using transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR). Additionally, water wettability measurements (WWM) were carried out to assess the hydrophobicity and hydrophilicity of the studied surface. We found that the nanocomposite deposited on a semitransparent silver mirror strongly increased the fluorescence intensity of dansyl dye (about 87-fold) compared with the control sample on the glass, proving that the system is a perfect candidate for a sensitive plasmonic platform.

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“…An absorption peak of rGO was observed at 272.7 nm, and a highly intense absorption peak of Ag@SiO 2 was observed at 410.2 nm [ 26 , 27 ]. The rGO-Ag@SiO 2 nanocomposite showed absorption peaks for rGO and Ag@SiO 2 at wavelengths of 276.8 and 408.6 nm, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…After the rGO-Ag@SiO 2 nanocomposite was formed, the individual vibrations present in the rGO and Ag@SiO 2 were confirmed to be the C–OH (1212 cm −1 ), C=C (1553 cm −1 ), and O–H (3675 cm −1 ) vibration bands of rGO and the Si–O (827 cm −1 ), Si–OH (983 cm −1 ), –CH 2 (2900 cm −1 ), and –CH 2 (2985 cm −1 ) bands of Ag@SiO 2 . The presence of the individual bands of rGO and Ag@SiO 2 at rGO-Ag@SiO 2 proved that the nanocomposite was successfully formed owing to a simple probe sonication process [ 27 ].…”

Section: Resultsmentioning

confidence: 99%

Differential Pulse Voltammetric Electrochemical Sensor for the Detection of Etidronic Acid in Pharmaceutical Samples by Using rGO-Ag@SiO2/Au PCB

et al. 2020

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An rGO-Ag@SiO2 nanocomposite-based electrochemical sensor was developed to detect etidronic acid (EA) using the differential pulse voltammetric (DPV) technique. Rapid self-assembly of the rGO-Ag@SiO2 nanocomposite was accomplished through probe sonication. The developed rGO-Ag@SiO2 nanocomposite was used as an electrochemical sensing platform by drop-casting on a gold (Au) printed circuit board (PCB). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) confirmed the enhanced electrochemical active surface area (ECASA) and low charge transfer resistance (Rct) of the rGO-Ag@SiO2/Au PCB. The accelerated electron transfer and the high number of active sites on the rGO-Ag@SiO2/Au PCB resulted in the electrochemical detection of EA through the DPV technique with a limit of detection (LOD) of 0.68 μM and a linear range of 2.0–200.0 μM. The constructed DPV sensor exhibited high selectivity toward EA, high reproducibility in terms of different Au PCBs, excellent repeatability, and long-term stability in storage at room temperature (25 °C). The real-time application of the rGO-Ag@SiO2/Au PCB for EA detection was investigated using EA-based pharmaceutical samples. Recovery percentages between 96.2% and 102.9% were obtained. The developed DPV sensor based on an rGO-Ag@SiO2/Au PCB could be used to detect other electrochemically active species following optimization under certain conditions.

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Nonlinear optical properties of Ag@SiO2 core-shell nanoparticles investigated by continuous wave He-Ne laser

Cited by 51 publications

References 29 publications

SiO2-Ag Composite as a Highly Virucidal Material: A Roadmap that Rapidly Eliminates SARS-CoV-2

SiO2-Ag Composite as a Highly Virucidal Material: A Roadmap that Rapidly Eliminates SARS-CoV-2

Dansyl-Labelled Ag@SiO2 Core-Shell Nanostructures—Synthesis, Characterization, and Metal-Enhanced Fluorescence

Differential Pulse Voltammetric Electrochemical Sensor for the Detection of Etidronic Acid in Pharmaceutical Samples by Using rGO-Ag@SiO2/Au PCB

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